Yes, markets have existed for a lot of time, well before established economic theory.

I don't think this surprise anyone, especially given that Adam Smith, who is known as the father of modern economics, wrote a book describing stuff that was obviously already happening before his ideas were published. Not to mention Italian bankers, tulips bubbles, gold coins and so on.

However, this doesn't mean that things do not (or cannot evolve). Markets are observed by someone, a theory is born, markets evolve, maybe following a theory, an existing theory is generalized, and so on.